Linkage mechanism providing a virtual pivot axis for hair removal apparatus with pivotal head

Abstract

A linkage mechanism for a shaver or depilator has a head carrying at least one hair removal member mounted for rocking about a virtual axis that remains nearly static during pivoting. The linkage mechanism five links, which include a pair of spaced support arms pivoting on the head. A first transverse link member rotates about a third axis and pivots on each of the support arms. Second and third transverse link members pivot on the body and on respective ones of the support arms.

1. A linkage mechanism for a hair removal appliance having a head ( 1 ) carrying at least one hair removal member and mounted for rocking about a virtual axis, said linkage mechanism being mountable on an appliance body ( 2 ) and comprising:
 a pair of spaced support arms ( 4 , 5 ) for pivotable attachment to the head ( 1 ) at first and second pivot axes ( 11 , 12 ), said first and second pivot axes being spaced apart by a first distance; 
 a first transverse link member ( 6 ) for pivotably mounting on said body ( 2 ) for rotation about a third axis ( 17 ) and being pivotably attached to each of said support arms ( 4 , 5 ), at fourth and fifth pivot axes ( 15 , 16 ) spaced apart by a second distance less than the first distance; and 
 second and third transverse link members ( 7 , 9 ) for pivotably mounting on the body ( 2 ) at respective first ends thereof and being pivotably attached at respective second ends thereof to respective ones of said support arms ( 4 , 5 ) at sixth and seventh pivot axes ( 13 , 14 ) spaced apart by a third distance, said first, second, third, fourth, fifth, sixth and seventh axes being mutually parallel. 
 
   
   
     2. A mechanism according to  claim 1 , wherein said third distance is less than said first distance. 
   
   
     3. A mechanism according to  claim 2 , wherein said third distance is less than said second distance. 
   
   
     4. A mechanism according to  claim 2 , wherein said second distance is less than said third distance. 
   
   
     5. A mechanism according to  claim 1 , wherein said respective first ends of the second and third transverse link members ( 7 , 9 ) are pivotally mounted on the body at eighth and ninth pivot axes ( 8 , 10 ) which are spaced apart, and parallel to said first and second axes. 
   
   
     6. A mechanism according to  claim 5 , wherein a plane perpendicular to said parallel axes intersects said third, eighth and ninth axes ( 17 , 8 , 10 ) at spaced points forming an isosceles triangle. 
   
   
     7. A mechanism according to  claim 5 , wherein said eighth and ninth axes ( 8 , 10 ) are colinear. 
   
   
     8. A mechanism according to  claim 5  or  7 , wherein said third, eighth and ninth axes ( 17 , 8 , 10 ) and said virtual axis are parallel. 
   
   
     9. A mechanism according to  claim 1  wherein the distance between said first and sixth axes ( 11 , 13 ) equals the distance between said second and seventh axes ( 12 , 14 ). 
   
   
     10. A mechanism according to  claim 1  wherein the distance between said first and sixth axes ( 11 , 13 ) is greater than the distance between said second and seventh axes ( 12 , 14 ). 
   
   
     11. A mechanism according to  claim 1  wherein the distance between said first and fourth axes ( 11 , 15 ) equals the distance between said second and fifth axes ( 12 , 16 ). 
   
   
     12. A mechanism according to  claim 11  wherein the distance between said first and sixth axes ( 11 , 13 ) is less than the distance between said first and fourth axes ( 11 , 15 ) and the distance between said first and sixth axes ( 11 , 13 ) equals the distance between said second and seventh axes ( 12 , 14 ). 
   
   
     13. A mechanism according to  claim 11  wherein the distance between said first and sixth axes ( 11 , 13 ) is greater than the distance between said first and fourth axes ( 11 , 15 ) and the distance between said first and sixth axes ( 11 , 13 ) equals the distance between said second and seventh axes ( 12 , 14 ). 
   
   
     14. A mechanism according to  claim 11  wherein the distance between said first and sixth axes ( 11 , 13 ) is greater than the distance between said first and fourth axes ( 11 , 15 ), the distance between said second and seventh axes ( 12 , 14 ) is less than the distance between said second and fifth axes ( 12 , 16 ) and the distance between said first and sixth axes ( 11 , 13 ) is greater than the distance between said second and seventh axes ( 12 , 14 ). 
   
   
     15. A mechanism according to  claim 1 , wherein the first, second and third transverse link members ( 6 , 7 , 9 ) are pivotably attached to said support arms by respective film hinges. 
   
   
     16. A mechanism according to  claim 1 , wherein the second and third transverse link members are attached to the body by respective film hinges ( 8 , 10 ). 
   
   
     17. A mechanism according to  claim 1 , wherein the second and third transverse link members are moveable relative to one another. 
   
   
     18. A mechanism according to  claim 1 , wherein the support arms ( 4 , 5 ) are not parallel to one another. 
   
   
     19. A mechanism according to  claim 1 , wherein the first transverse link member ( 6 ) is configured as a bell crank. 
   
   
     20. A linkage mechanism for a hair removal appliance having a head ( 1 ) carrying at least one hair removal member and mounted for rocking about a virtual axis generated by said linkage mechanism, said linkage mechanism being mountable on an appliance body ( 2 ) and comprising:
 a pair of spaced support arms ( 4 , 5 ) pivotally connectable to the head ( 1 ) at first and second pivot axes ( 11 , 12 ); 
 a first common link member ( 6 ) for pivotably mounting on said body ( 2 ) for rotation about a third axis ( 17 ) and being pivotably attached to each of said support arms ( 4 , 5 ), at fourth and fifth pivot axes ( 15 , 16 ); and 
 second and third transverse link members ( 7 , 9 ) for pivotably mounting on the body ( 2 ) at respective first ends thereof and being pivotably attached at respective second ends thereof to respective ones of said support arms ( 4 , 5 ) at sixth and seventh pivot axes ( 13 , 14 ). 
 
   
   
     21. A mechanism according to  claim 20 , wherein the first, the fourth and the sixth axes ( 11 ,  15 ,  13 ) define a first set of three pivot axes and the second, the fifth and the seventh axes ( 12 , 14 ) define a second set of three pivot axes, and wherein the three pivot axes within at least one set of said first and second sets of pivot axes are co-planar. 
   
   
     22. A linkage mechanism for a hair removal appliance having a head ( 1 ) carrying at least one hair removal member and mounted for rocking about a virtual axis generated by said linkage mechanism, said linkage mechanism being mountable on an appliance body ( 2 ) and comprising:
 first and second spaced support arms ( 4 , 5 ) for pivotally connecting to the head ( 1 ) at first and second pivot axes ( 11 , 12 ); 
 a first common link member ( 6 ) for pivotably mounting to said body ( 2 ) for rotation about a third axis ( 17 ) and being pivotably attached to each of said support arms ( 4 , 5 ), at fourth and fifth pivot axes ( 15 , 16 ); and 
 at least one stabilizing link member ( 7 ) for pivotably mounting on the body ( 2 ) and being pivotably attached to only one of said first and second support arms ( 4 , 5 ). 
 
   
   
     23. A linkage mechanism according to  claim 22 , further comprising a second stabilizing link member ( 9 ) for pivotably mounting on the body ( 2 ) at a first end thereof and being pivotably attached at a second end thereof to the other of said first and second support arms ( 4 ,  5 ) at another pivot axis ( 14 ). 
   
   
     24. A hair removal apparatus, comprising:
 the linkage mechanism according to  claim 1  the head ( 1 ) carrying the at least one hair removal member supported on said linkage mechanism mounted on said body ( 2 ) for rocking about said virtual rocking axis. 
 
   
   
     25. A hair removal apparatus according to  claim 24 , wherein said at least one hair removal member is a cutter unit for performing shaving. 
   
   
     26. A hair removal apparatus according to  claim 24 , wherein said at least one hair removal member is an epilation head for plucking hair. 
   
   
     27. A method of mounting a component such as a head ( 1 ) carrying at least one hair removal member mounted, for rocking about a virtual axis, the method comprising the steps of:
 pivotably attaching a pair of spaced support arms ( 4 , 5 ) to the head ( 1 ) at first and second pivot axes ( 11 , 12 ), said first and second pivot axes being spaced apart by a first distance; 
 pivotably mounting a first transverse link member ( 6 ) on a body ( 2 ) for rotation about a third axis ( 17 ) and pivotably attaching the first link member ( 6 ) to each of said support arms ( 4 , 5 ), at fourth and fifth pivot axes ( 15 , 16 ) spaced apart by a second distance less than the first distance; and 
 pivotably mounting second and third transverse link members ( 7 , 9 ) on the body ( 2 ) at respective first ends thereof and pivotably attaching the second and third link members at respective second ends thereof to respective ones of said support arms ( 4 , 5 ) at sixth and seventh pivot axes ( 13 , 14 ) spaced apart by a third distance, said first, second, third, fourth, fifth, sixth and seventh axes being mutually parallel.